回文数是指从左到右和从右到左读都相同的数字。以下是一些回文数的例子：
单个数字：0, 1, 2, 3, 4, 5, 6, 7, 8, 9
两位数：11, 22, 33, 44, 55, 66, 77, 88, 99
三位数：101, 111, 121, 131, 141, 151, 161, 171, 181, 191, 202, 212, 222, 232, 242, 252
四位数：1001, 1111, 1221, 1331, 1441, 1551, 1661, 1771, 1881, 1991, 2002, 2112, 2222, 2332, 2442, 2552
五位数及以上：10001, 10101, 10201, 10301, 10401, 10501, 10601, 10701, 10801, 10901, 11011, 11111, 11211, 11311, 11411, 11511, 11611, 11711, 11811, 11911, 12021, 12121, 12221, 12321, 12421, 12521, 12621, 12721, 12821, 12921, 13031, 13131, 13231, 13331, 13431, 13531, 13631, 13731, 13831, 13931, 14041, 14141, 14241, 14341, 14441, 14541, 14641, 14741, 14841, 14941, 15051, 15151, 15251, 15351, 15451, 15551, 15651, 15751, 15851, 15951, 16061, 16161, 16261, 16361, 16461, 16561, 16661, 16761, 16861, 16961, 17071, 17171, 17271, 17371, 17471, 17571, 17671, 17771, 17871, 17971, 18081, 18181, 18281, 18381, 18481, 18581, 18681, 18781, 18881, 18981, 19091, 19191, 19291, 19391, 19491, 19591, 19691, 19791, 19891, 19991
以上列出的回文数包含了不同位数的回文数，从单个数字到五位数